Pêche et production animale

Abstrait

Indices from Chrysicthys nigrodigitatus (Lacépède, 1803), Tilapia guineensis (Bleeker, 1862), Clarias gariepinus (Burchell, 1822) and Clarias anguillaris (Linnaeus, 1758) as Bioindicators of Organic Pollution in Ogun River, Southwest Nigeria

Olufelo OS, Olufade OB, Matilukuro YA Efuntoye MO and Sowunmi AA

The current health status of Ogun river Southwest Nigeria was investigated using body and derived indices from Chrysicthys nigrodigitatus, Tilapia guineensis, Clarias gariepinus and Clarias anguillaris. Quality of effluents from the two abattoir located at Isheri-Olofin and Lafenwa, and the adjacent receiving water of R. Ogun were evaluated. Physico-chemical parameters exceeded the NESREA (2011) national criteria for effluent and USEPA (2002) for aquatic life. NH3-N and PO43 indicated elevated levels of organic pollution but trace metal contents has direct implication for aquatic life. Reduction in growth indices of total length, standard length, total body weight and fecundity were observed in all the species compared with previous records. Derived indices of gonadosomatic index and Fultons’ condition factor (K) exhibited similar pattern. Liversomatic index (LSI) were elevated indicative of disruption in body mechanism of the fish species arising from pollution. The remaining indices of gonadal index (GI), visceral somatic index (VSI) and percentage dress out (PDO) were significant and first reports any species from Ogun river.